There are a number of prior art bi-level infrared thermal detectors. Examples include U.S. Pat. No. Re. 36,136; U.S. Pat. Nos. 5,286,976 and 5,450,053.
The technology disclosed in U.S. Pat. No. Re. 36,136; U.S. Pat. Nos. 5,286,976 and 5,540,053 has proven to be a commercial success (a cross section of a pixel using this prior art technology is shown in FIG. 1); however, this technology is relatively complex due in part to the utilization of a so-called wet etch process used in the fabrication. A relativly large number of masks must be used in order to produce an array of pixels. This produces more mass and hence requires more energy to change temperature.
The technical disclosures of U.S. Pat. No. Re. 36,136; U.S. Pat. Nos. 5,286,976 and 5,450,053 are incorporated herein for reference.